PORTSMOUTH — John Vallo and Andrea Walkonen had never run the Seacoast Half Marathon before Sunday's seventh annual race, but the pair left their mark.

Vallo, 22, of Portland, Maine, was actually running in the first New Hampshire race of his life and cruised to the win by besting the field of around 1,100 runners, crossing the finish line at Portsmouth High School in a time of 1 hour, 13 minutes and 23 seconds.

Walkonen, 26, of Lebanon, set a new course record by winning the women's division in a time of 1:17:19 and finished an impressive third overall.

“It was a really nice day — nice cloud cover, it wasn't sunny at all and it could've been a lot worse, especially after the snowstorm we just got,” Vallo said. “It started out pretty good. I had some competition through five (miles) but he kind of fell off after that. I just tried to stay strong bringing it in and I really wanted to break 1:13:00; I just fell short of that.”

Mark Mayall, 41, of Maynard, Mass., finished a distant second (1:17:01), while Hampton's Chris Ritchie, 29, placed third in the men's division (1:18:26).

Walkonen shattered the women's course record of 1:21:49 that was set last year by Kim Webster of Framingham, Mass. Rochester's Denise Sandahl, 32, continued her strong season by finishing second (1:25:41). Beth Dollas, 35, of Amesbury, Mass., was third (1:27:09).

“My coach (Jeff Johnson) told me to cruise through the first nine miles and kind of use it as a tempo, and that's what I did,” Walkonen said. “From there, pick it up and, if not, keep cruising. I think I picked it up, but after 10 miles it starts to feel the same. I felt strong the whole way through.”

Vallo just graduated this spring from the University of Southern Maine, where he picked up a couple of All-New England selections. He was running in his second half marathon, after he won the Harvest Half Marathon three weeks ago in Biddeford, Maine, in 1:15:49.

He said that he's still getting used to running longer distances after primarily running 5Ks, and tried some adjustments on Sunday.

“I'm used to the 5Ks and going out a little harder, so it's tough to try to bring it in and not push yourself too much at the beginning, and not have enough at the end,” Vallo said. “I'll say that miles 8 and 9 were a little hard, but I was able to finish stronger than I thought I would.

“I thought I'd have more people pushing me, so I was a little shocked it was an emptier lead pack today, but I'm happy with it.”

Now that the native of Beacon, N.Y., has graduated college, he said plans on competing regularly in road races.

“I'm going to run some 5Ks, 10s and maybe a marathon in the future, but you've got to be motivated for that and get some training; you can't rush that,” Vallo said.

Bob Wiles of Kittery, Maine, set the course record of 1:09:19 in 2010.

Walkonen grew up in Jaffrey and graduated from Conant High School in 2004, before embarking on a standout career at Boston University. She reached the nationals in the indoor 5K and outdoor 10K, and finished eighth in the NCAA 10,000-meter championships in 2008. She currently holds the BU school record in the 10,000.

Walkonen broke away from Sandahl quickly and found herself among the lead pack of men. Her conservative plan of taking the race out slow still resulted in 5:46 splits.

“For the first couple of miles I was chatting with the guys, which is a lot of fun, because I'm not used to that in a lot of races,” Walkonen said. “I think if my coach wouldn't have told me to tempo the first nine miles, I probably would've been able to stay (with Vallo and Mayall) a little longer, but I have this bad habit of jack-rabbiting out too fast.

“I'm kind of new at the half marathon and marathon distances, so I've got to get used to getting out slower and picking it up at the end.”

Walkonen said she plans on running her first marathon, the Houston Marathon, in January.

Vallo, Mayall and Ritchie were followed in the men's top 10 by Tim Horan (1:18:39) of Dover; Ryan Proulx (1:20:17) of Portsmouth; Ryan Marshall (1:20:44) of Stratham; Michael Fraysse (1:23:11) of Derry; Jonathan Spelke (1:23:33) of Topsham, Maine; Brian Betournay (1:24:04) of Dover; and Jonathan Kunhardt (1:24:14) of Greenfield, Mass.

Walkonen, Sandahl and Dollas were followed in the women's top 10 by Devin Parker (1:27:27) of Cambridge, Mass.; Diana Eisenhoure (1:33:11) of Barrington; Kelley McLean (1:33:39) of Cochester, Vt.; Caroline Merrill (1:33:40) of Portsmouth; Jennifer Sprague (1:35:50) of Dover; Lauren Finelli (1:35:58) of Portsmouth; and Laurianne Schlosser (1:38:20) of Portsmouth.